Roof Batten Spacing Calculator (Tile Roofing)

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Market

Imperial · sales tax

Roof Slope Length

The total length of the roof measured along the slope, from eave to ridge.

Along the slope, because battens are gauged down it. The run does not divide evenly either: the eave course is set at a shorter gauge so the first tile sits correctly over the fascia, and the top course has to land under the ridge. So the slope length is a whole number of gauges PLUS two special courses, and the adjustment is made across the field rather than left to the last batten.

Batten Gauge (Spacing)

The center-to-center spacing between batten rows, set by the tile manufacturer's gauge table.

Batten gauge is determined by the specific tile profile's headlap and exposure requirements — always use the tile manufacturer's specified gauge.

Batten rows needed

17 rows

High confidence

Then change the inputs to see how far the answer moves.

Show calculation logic

How this was calculated

Formula source(s)

Batten rows = ceil(roof slope length / batten gauge/spacing) + 1, the standard method for laying out tile roof battens

Inputs used

Roof Slope Length: 16.5 ft
Batten Gauge (Spacing): 13 in

Final result17 rows

What this calculation does not cover

Divides the slope by one fixed gauge, and a roof is not set out that way. The eave course and the top course have their own positions fixed by the tile's headlap at each end, and the courses between are then equalised so the gauge divides the remainder exactly — meaning the working gauge sits at or below the manufacturer's maximum, never at it. Running the maximum straight up from the eave leaves the last course short of headlap at the ridge, which is where the rain gets in.
Returns rows, not battens to order. The quantity is rows multiplied by the width of the roof, plus the lap at every batten join — and those joins have to be staggered between adjacent courses and land on a rafter, so a stock batten length that does not suit the rafter centres wastes an offcut at every join.
Says nothing about counter-battens. On a roof drained over the underlay, vertical counter-battens run up the slope beneath these horizontal ones so water can get past them to the eave. Without them each batten is a small dam holding water on the underlay, and the second quantity is roughly one counter-batten per rafter over the full slope length.

Estimated cost — your price

Price per row ($)

This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.

Part of bigger jobs

This trade is one line of several job takeoffs. Run the whole job and every other trade comes back with it, off the same measurements.

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Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.

Sources checked 2026-09-06 · in the site-wide review of 2026-09-06 · v1.0.1

Regulatory standards & verification citations1

Batten rows = ceil(roof slope length / batten gauge/spacing) + 1, the standard method for laying out tile roof battens

Cite this page

Your workspace

Most jobs need more than one number. Add the calculators you need next and they open right here, underneath this one — your figures stay on screen and nothing is lost to a page change.

Tools and safety for this job

To batten and tile or slate the roof. Generic types, no brands, no prices.

Protection this work requires

Cutting or grinding concrete, masonry, screed, tile or fibre-cement board releases respirable silica: cut wet or extract at the tool, and wear a P2/N95 respirator at minimum — a nuisance dust mask does not filter it.
Saws, grinders and breakers run above 85 dB, where hearing damage accumulates and does not recover: defenders or plugs for every cut, not just the long ones.
Breakers and grinders cause permanent nerve damage: limit continuous trigger time, keep hands warm, and stop if fingers tingle or blanch.
Boards, blocks and bagged material cause most lasting back injuries on small sites: two people or a lifter for full sheets, and never a bag on one shoulder up a ladder.
Most fatal falls on small jobs are from under three metres: use a tower or a ladder tied at the top, and never work off the top two rungs.

Show the 5 tools this job needs

Essential

Chalk line
Claw hammer
Hand saw
Tape measure

Recommended

Angle grinder

Also needed as materials: chalk refill, cutting and diamond discs.

what each roofing tool is for, and the spec that decides which to buy where one does.

Now that you have the number

These guides cover the work this quantity is for — the first ones run this calculator inside the section that raises the question.

Laying a Clay Barrel Tile Roofuses this calculator

Barrel tile is heavy, brittle and counted piece by piece — and how it reaches the roof is settled by a ladder rule, not by how strong the crew is.

Setting Out a Slate or Cedar Roofuses this calculator

Gauge, margin and headlap fixed with a chalk line on bare rafters, and the course arithmetic that has to close before slate or cedar is ordered.

Setting Out Roof Battens: Gauge and Headlapuses this calculator

The eaves line, the top line, and a whole number of equal steps between them — how a batten gauge gets settled without ever giving up headlap.

How to calculate roof batten spacing (tile roofing) in 3 steps

Roof Slope LengthThe total length of the roof measured along the slope, from eave to ridge.

Batten Gauge (Spacing)The center-to-center spacing between batten rows, set by the tile manufacturer's gauge table.

Batten rows neededThe tool computes the batten rows needed from those figures and shows the formula, its sources, and a confidence rating alongside it.

Roof Slope Length	Batten rows needed (rows)
10 ft	11
15 ft	15
20 ft	20
25 ft	25
30 ft	29

Roof Slope Length

Batten rows needed (rows)

10 ft

15 ft

20 ft

25 ft

30 ft

Frequently asked questions

Is the gauge only limited by the covering?

No — the batten has to hold up as a beam as well as land in the right place, and that is the limit people forget. A batten spans between rafters carrying the covering, the wind uplift and, at some point, a roofer standing on it, so its permitted span depends on its section and grade, not on the gauge you would like. Widen the rafter centres and the same batten may no longer make the span whatever the course arithmetic says, which is why a re-roof over old wide-set rafters sometimes needs a deeper batten rather than a different gauge. Settle the covering's headlap first, then check the batten can actually cross the rafters you have.

Why is an extra row added beyond the simple division?

A batten row is needed at both the eave and the ridge end of the slope, so the row count is one more than the number of full gauge spacings that fit along the slope length.

What sets the batten gauge for a given tile?

Batten gauge is determined by the specific roof tile profile's headlap and exposure requirements from the manufacturer's fixing specification — it is not a fixed universal number across tile types.

Does this account for the eave batten, which is often doubled or thicker?

No — this calculates the number of gauge-spaced rows only. Many tile systems use a thicker or doubled starter batten at the eave, which should be checked separately against the manufacturer's fixing details.